The present invention relates generally to an improved biopsy needle structure, and more specifically to a palm engaging knob which may be releasably mounted on the proximal end of the needle, thereby rendering the device more comfortable in the hands of the user.
Bone marrow biopsy needles are well known, and are widely used in the collection of biopsy tissue. Bone marrow biopsy structures are illustrated and disclosed in U.S. Pat. Nos. 3,628,524, and 3,598,108. The device of the present invention is intended to be slipped over the proximal end of the needle structure following removal of the stylet, this normally occurring at the time the surgeon is commencing penetration of the bone surface.
Normally, bone marrow biopsy needles may have a proximal end which is relatively small in cross-section, and in certain instances, may be an extension of the elongated needle structure. In order to facilitate penetration of the bone, the distal end of the needle is normally sharpened, and this cutting edge, while moving relative to the surface of the bone, and with a force being applied to the bone, will accomplish penetration. In certain instances, and in some structures, the tip of the needle may be serrated or provided with rasp-like elements, depending upon the application. The force required to penetrate the bone is, of course, applied by the surgeon through the palm of his hand as the biopsy needle structure is being rotated arcuately about its axis. In order to reduce the stress concentration on the palm of the hand, the removable pad element of the present invention is provided, with the device further having a means for eliminating transfer of air into the lumen of the needle when being mounted on the needle end.